The Giants Novels (Inherit the Stars, The Gentle Giants of Ganymede, and Giants' Star)

Discover the first three books in the ground-breaking 21st century hard-science fiction saga by James P. Hogan:
INHERIT THE STARS
The skeletal remains of a human body are found on the moon. His corpse is 50,000 years old, and nobody knows who he was, how he got there, or what killed him.
THE GENTLE GIANTS OF GANYMEDE
A long-ago wrecked ship of alien giants is discovered by Earth's scientists on a frozen satellite of Jupiter. Then, spinning out of the vastness of space, a ship of the same strange, humanoid giants has returned....
GIANTS' STAR
Humans finally thought they comprehended their place in the universe...until Earth found itself in the middle of a power struggle between a benevolent alien empire and a cunning race of upstart humans who hated Earth!